Although the study of Learning is extremely relevant to the endeavor of functional rehabilitation of brain injured patients, there has been little effort to directly apply* learning principles to the rehabilitation setting. Contextual interference refers to the finding that practice occurring interspersed with other tasks leads to greater long term retention than blocked practice (random practice effect). Also, practice on more than one variant of a task leads to better long term retention' on. and better ability to use the skill flexibly (variable practice effect). It appears therefore, that contextual interference results in outcomes that are precisely the goals of neurorehabilitation (long term flexible retention). There are however reasons that suggest some groups may not benefit from, or may even be hindered by, contextual interference. The primary goals of the proposed studies are to; (1) examine the effect of contextual Interference on motor skill relearning in stroke patients: (2) identify factors in patients undergoing rehabilitation post stroke that indicate whether contextual interference training is beneficial; (3) relate the location and changes in size of the infarction visualized with Magnetic Resonance Imaging with skill relearning improvements over time; and (4) develop training paradigms employing contextual interference that could be adopted readily in the neurorehabilitation clinic.